Deformation Behavior and Properties of a CuZrTiNi BMG Kinetic Spray Coating

The deformation behavior and mechanical properties of a Cu₅₄Zr₂₂Ti₁₈Ni₆ bulk metallic glass during and after deposition by kinetic spraying were investigated. The bulk metallic glass feedstock particles were manufactured by inert gas atomization and were subsequently deposited onto mild steel substrates by means of kinetic spraying at different powder carrier gas temperatures [room temperature, 450°C (within the supercooled liquid region), and 550°C (above crystallization temperature)]. In addition, the phase compositions of the feedstock and as-sprayed BMG coatings were investigated using X-Ray Diffraction (XRD), Differential Scanning Calorimetry (DSC), and Transmitted Electron Microscopy (TEM). With an increase of the powder feed temperature, it was deduced that more intimate contact of the particles with the substrate was achieved which decreased the porosity of the resulting coating. However, crystallizations, which seemed to be induced by severe deformation and accumulated heat, were observed at localized regions in the coating. In addition, micro-hardness and bond strength were affected by the crystallization degree of the as-sprayed coatings